Automated Electromagnetic Crane Greg DeKing

Fran Simmonds

Principles of Design

Functionality Mechanical Design Sensor Design Embedded Design Cost Problems Questions

Functionality

The Automated Electromagnetic Crane locates, acquires, and removes steel blocks from a target area to a designated container in an uninterrupted sequence.

Specifications

Runs in fully automated mode. User may pause operation and

move blocks. All blocks are relocated after every

“grab” operation. Closest-to-bucket order of pickup.

Limitations

All blocks must be fully inside target area.

If a block is dropped the “drop” operation will still proceed.

Blocks must be of a conductive material with a strong magnetic field.

Designer imposed constraints High success rate.

Sensors. Low cost. Stationary. Battery power.

Components

HC12 Duramag ER1-071 Electromagnet 3 12V Stepper Motors 8 74151 8-1 Mux OPB 745 Optoisolator

Duramag ER1-071 Electromagnet

Part Number Diameter Length Thread

Tap Dept

h

Lead Location

Lead

Length Watt

s *Holding

Value Net

Weight

12 VDC

24 VDC

110 VDC

A B T   G   Lbs.

ER1-071

ER2-071

- 3/4 1-1/4 10-32 3/8 3/16 24" 1.5 6 1.7 oz.

Part Number Diameter Length Thread

Tap Dept

h

Lead Location

Lead

Length Watt

s *Holding

Value Net

Weight

12 VDC

24 VDC

110 VDC

A B T   G   Lbs.

ER1-071

ER2-071

- 3/4 1-1/4 10-32 3/8 3/16 24" 1.5 6 1.7 oz.

Motors

12V Airpax stepper motor 2 12V NMB stepper motors Stepper interface boards

Optoisolator

Inductive spike caused from switching magnet off.

25.5 Volt magnitude. Separate 12V source. Magnet on/off controlled by

optoisolator circuit.

Mechanical Design

Mastercam – side view

Mechanical Design

Tower Support

Mastercam -- top view

Sensor Placement

Sensor Design

Conductive rings separated by non-conductive material

Inside rings of row in series Outside rings of column in series

Sensor Function

Input signal applied to inner ring Block completes circuit Corresponding mux control HC12 reads voltage “hit”

Interfacing

MULTIPLEXER SYSTEM

Sensor Map

37 bytes. Each byte 1 Column. Each bit represents row number.

Sensor sweep will fill sensor map one row at a time.

When all 37 columns for each row complete next row will begin.

Embedded Designbegin read AD

store AD in TEMP

change MUX controls

Loop ITERATION += 1

bit test bit 0

branch {bit not set} to next

set bit MAP_POINTER + BIT_POINTER

next MAP_POINTER += 1

Shift TEMP

Test ITERATION

branch {less than 8 } to loop

ITERATION = 0

Test MAP_POINTER

Branch { less than 37 } to begin

BIT_POINTER += 1

Test BIT_POINTER

Branch {less than 8} to begin

BIT_POINTER = 0

Foreseeable Problems

Multiplexing of I/O. Blocks contacting multiple sensors. Two Blocks on same sensor.

Cost

Electromagnet $40.00 Motors $15.00 Circuit Boards $30.00 Muxs $15.00 Aluminum $60.00

Total $180.00

Questions

Any Questions ?